
161Ammunition Design Practice
the sabot, τ. Similarly, on the sabot, we have the net internal stress, (dσ
zs
/dz)∆z; the inertial
resistance to acceleration, ρ
s
V
s
a; the shear stress imparted by the sub-projectile, τ; and the
component of pressure in the axial (z) direction. We proceed by initially nding an expres-
sion for the volume of the sabot free body. Details of this derivation are found in Ref. [6].
The incremental volume of the sabot can be shown as follows:
V
ssp
∆
π
Rz
()
(4.158)
Double-ramp sabot
Penetrator
σ
1
τ
p
s
Shear
stress
FIGURE 4.27
Shear stress variation in a double ramp-type sabot.
τ
σ
zp
σ
zp
dσ
zp
R
P
dz
Δ
+
Δz
FIGURE 4.28